Differential Gomes Amplifier using pentodes in ultra linear mode?

[ELS122]

I found this:

and wanted to modify it so it uses pentodes as the power tubes, and have a transformer with taps for the screen grids so I can switch the pentodes from "pentode" to "triode" mode and have the pentode mode be ultra-linear.
but where would I connect the screens for the top pentodes?
is this even possible?
also, I intend to put 2 chokes in series with the plates of the top pentodes to it's a parafeed style output stage
that's possible right? I don't really see a reason why that wouldn't be but correct me if I'm wrong.

[ELS122]

I kinda came up with this, but I have no idea what the values of some of the components are and how to run the pentodes in ultra linear mode AND what the screen resistor values should be.
also the transformer I should use (windings, resistance, etc.)

[ELS122]

also wouldn't tying the cathodes together be bad? since if they are together the tubes will be doing the same thing as each other?

[Circlotron]

I would run the screens of the upper pentodes to +600V through a resistor, and to the ultra linear tapping through a large capacitor, similar in principle to how the anodes of the upper outer triodes are fed.

I don’t think the two chokes at the top are going to do anything useful. More likely just cause problems. Parafeed is unnecessary in this topology.

[ELS122]

so I want to bias them with fixed bias, but how do I do that if 2 of the power tubes are cathode followers?

[gbaddeley]

12B4 is a low Ra and low mu triode. You would need to think very carefully about using pentodes / tetrodes in such a circuit, as they have much higher Ra and mu.